Abstract
The effect of uniaxial stress on the one-phonon Raman lines of CdS having , , and symmetries are studied for compressive force , either along the axis () or the axis () and using a low-temperature stress cryostat. The scattering geometries chosen resulted in the phonon propagation direction being either parallel or perpendicular to ; this in turn allowed the observation of pure , , , and lines. For , the lines or their components shift linearly with stress. The line at 256 splits into two clearly resolved components, the polarization features being consistent with the deformation-potential theory. The and the lines separate further, whereas the and the lines increase at the same rate. For , all the lines exhibit shifts linear in stress; the and the lines increase at the same rate, and the line at 256 does not split. From the results for and , the deformation-potential constants characterizing each line have been deduced. A comparison of the piezospectroscopy of the doubly degenerate line of CdS with that of the lines of -quartz is presented along with some new results for the latter. The LO overtones observed in geometry shift linearly for , the rates of shift increase linearly with increasing order. The magnitudes of these shifts suggest that all overtones are of nature.
- Received 12 December 1975
DOI:https://doi.org/10.1103/PhysRevB.13.5518
©1976 American Physical Society